Lou Carcolh, or the Carcolh, is a supposed mythical beast from Gascon folklore. It was described as being both a serpent and mollusc at the same time, taking characteristics from both types of animals. Its massive and long body carried an enormous shell upon its back, much like a snail's shell, that was believed to live in caverns in southwest France. Its gaping mouth was surrounded by several long, hairy, and slime covered tentacles that could extend for miles. These appendages stretched out from the cave it inhabited for a long distance and laid upon the ground among its own viscous slime. They would ensnare and drag back to its abode anything within reach. It would then swallow the victim whole with its gigantic mouth.

The Carcolh is a nickname given to the city of Hastingues, in the French department of Landes, due to its situation on a rounded-shape hill. Furthermore, the men of Hastingues used to say, as a pleasant warning to young and pretty women "The carcolh will catch you!".